The commercial processing of hard shell crabs involves first butchering and cleaning the crab, that is, removing the appendages and the carapace and cleaning away the viscera and other organs, and then, second, picking the meat from the crab. Many processors carry out the entire process by hand, and the labor costs unquestionably contribute to the high cost of the end product to the consumer. Various machines are known in the prior art for butchering the crab, but the present inventor is unaware of any machine in the prior art that is effective in carrying out the picking operation, that is, the operation in which the meat is removed from the butchered and cleaned body.
Representative of prior art proposals for machines for butchering crabs are the following U.S. patents:
Harris U.S. Pat. Nos. 3,253,299 and 3,302,236; PA1 Tolley U.S. Pat. Nos. 3,495,293 and 3,596,310; PA1 Tolley et al. U.S. Pat. No. 4,380,094; PA1 Davis et al. U.S. Pat. No. 4,073,041; PA1 Houghton et al. U.S. Pat. No. 3,370,319;
All of the aforementioned patents describe and illustrate machines that are, by and large, very complicated in structure, in that they involve relatively intricate holders for positioning the crab and complicated mechanisms for removing the claws, legs, carapace and viscera. Moreover, the end product produced by the machines proposed in those patents is a relatively clean body, that is, a butchered crab body that still contains the meat. Unquestionably, the clean body is more easily picked, but the final operation, the picking of the crab meat from the butchered and cleaned body is a hand operation.
The only prior art that the present inventor is aware of that proposes a machine for removing the meat from a crab is Altman U.S. Pat. No. 3,251,091. The present inventor is not aware, however, of any commercialization of the mechanism of this patent. The Altman patent, in particular, proposes a machine for "picking" the meat from a butchered and cleaned body by extruding it. According to the Altman patent the body is received in a specially shaped lower mold cavity, and an upper mold is pressed against the crab body, the upper mold being likewise specially shaped Considerable emphasis is placed in the Altman disclosure on the exact shapes of the molds, undoubtedly because the pressure has to be applied in a particular way to get the meat to extrude from the body. In view of the importance of the particular shape it also appears to be important that the size of the mold be suited for a particular size crab. Accordingly, one must envision using a range of mold sizes in a commercial operation and sorting the crabs by size in order to obtain effective use of the concept of the Altman patent.